<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    let a = 10;
    let b = 15 , c;
    c=b;
    b=a;
    a=c;
    console.log(a);
    console.log(b);

</script>
</html>